Is this just a terrible idea?

[Live the Journey]

So, In planning for my march '09 departure, one of my main concerns has been on staying warm, particularly at night...I'm very cold natured and sleep very cold, plus I have a circulatory condition (nothing too serious, just makes my extremities more prone to heat loss and potentially frostbite)

I have a 750 down sleeping bag that fits me very well and weighs in at 1lb. 15oz. and is Rated to 15* (which I sleep comfortably in to about 25-30*)

I just found and bought a 750 down summer bag rated to 40* for $34 that weighs 1lb. 2 oz.

Now...call me crazy, but couldn't I start out with both, using the 40* bag as a very warm liner and send it home when it gets a little less cold, keeping the 15*? This also keeps me from having to drop big money on yet another (warmer)sleeping bag to start and finish with. I know starting with 3 lbs of sleeping bag may seem a little much, but thats what I'm wondering. Does this seem like a good idea or does anyone have any other suggestions?

[jersey joe]

Interesting idea. I suppose you could do this but does the one bag fit nicely inside the other bag? An alternative could be to wear warmer clothing to sleep.

[Blissful]

Use a cocoon silk liner which adds nine degrees. Stay in a tent. Bring a few hand warmers too to use in the bag, (I did that on really cold nights. But be careful if you have circulatory problems)
And what you wear to sleep at night helps. Like mid weight polartec tights and top. And wear your hat.

[Johnny Thunder]

I have the exact same summer/winter bag setup....a few months back someone posted a convoluted math formula that eventually proved that you can use both "comfortably" down to about 0 degrees.

I started April 1st with a 15 degree bag and had no warmth issues. Start thinking about all your clothing and your bag in terms of what you'd sleep in if it got cold below your bag's rating.

But your resupply person is in Raleigh so they'll be able to get thing to you quickly.

[bigcranky]

Yes, you can layer two sleeping bags. Works pretty well as long as they fit well and one doesn't compress the insulation of the other.

If your main bag is comfortable for you down to 25 or so, you'll likely get some colder nights than that. You can always try this bag combo at home when we get a cold snap.

[WritinginCT]

You could also just open up the second bag and use it as a quilt over top the other bag you're snuggled into. Nothing gets squished and it will be easy enough to shove it off if you find yourself too warm with both.

[Johnny Swank]

I'd say bag the March start and move it back to April 10 if cold is going to be health issue. You'll have plenty of time to finish. You'll still get some cold snaps here and there, but not usually as harsh or long-lasting as those in March. You'd be able to get rid of that second sleeping bag, and you can alaways heat up a few water bottles and use a space blanket inside your bag if it gets really chilly.

[Tagless]

What sleeping pad do you use? This could enter into the equation.

In addition to the great feedback above, here is one other thought. You could carry a 1/8" Gossamer Gear Thinlight insulation pad. At just two ounces, weight isn't much of a factor. Some hikers use this between their sleeping bag and pad. It's pretty inexpensive at $9.00.

You might want to consider testing these various combinations - camping overnight in your yard. This could resolve your questions and give you needed confidence in your equipment choices - particularly if you set out in March.

[KG4FAM]

You could also just open up the second bag and use it as a quilt over top the other bag you're snuggled into. Nothing gets squished and it will be easy enough to shove it off if you find yourself too warm with both.I like doing it the other way using the light bag inside the heavy one. I like the way that you can use your hands and arms to keep it around you during the night. I practice my kung fu while I sleep so doing the quilt on the outside would surely get tossed to the side and then I would have to open my bag to rearange it and loose all the hot air.

[TrippinBTM]

Here's the problem: once it gets a little warmer at night, say, 35 degrees, you're heavy bag will start to be too heavy, while the light one won't be enough. So you may end up too hot. Or anyways be carrying two bags for a while even when you're using only one. I guess you could bounce the summer bag ahead, tho...

the problem with an April start is that he may get nailed by cold weather at the end. It was getting downright cold when I was in Maine, at least towards the end, and that was only mid September.

[Live the Journey]

Thanks for the feedback so far everyone. To answer some questions...
For sleeping pads I have an REI litecore full length, which is pretty darn warm, and when its not cold I use one of the original Thermarest prolite's in a 3/4 length. I usually try to sleep in my Cap 1s, but if need be I'll put whatever else I have on...and I always sleep with a hat on.
Also, I bivy/tarp, which adds quite a bit of warmth as well, but if I don't need the bivy for whatever reason (pretty night or just too warm), I just sleep under the tarp. I do have a sea to summit thermolite reactor bag liner which I normally use, but would probibly drop if I was going to use the 40* bag as a liner.
As for a later start, I'd rather leave earlier and give myself plenty of time, as I'm not the speediest of people...but who knows. It's always an option.

[TrippinBTM]

Some of it is just putting up with nature. You learn to accept it and adapt, some do it better than others but it's bound to happen. Exposure to cold will help you acclimate to it, you'll get to where you won't really notice cold that before would make you shiver badly.

[waywardfool]

Gonna test it out this Thursday?? :) Low for central N.C. is to be about 12* overnight! Give us a report...

[River Runner]

You could also consider wearing an insulated jacket and insulated pants in your bag for extra warmth instead of the second bag, which will is more useful as it will keep you warm around camp before you get in your sleeping bag and makes it easier to crawl out of a warm bag on a cold morning.

[weary]

I'd say bag the March start and move it back to April 10 if cold is going to be health issue. You'll have plenty of time to finish. You'll still get some cold snaps here and there, but not usually as harsh or long-lasting as those in March. You'd be able to get rid of that second sleeping bag, and you can alaways heat up a few water bottles and use a space blanket inside your bag if it gets really chilly.
I started in mid April with a down bag that was essentially a 1.7 pound sleeping bag liner.

I augmented it with a down jacket, wool socks, and insulated underwear. It worked. Not in a terribly easy way, but the combination solved the problem. Despite cheap insulation and cool nights, I remained comfortably warm, most nights, and adequately warm, on the few exceptions.

My advice: Plan, think, and don't worry about those who think you can't make it. As LW is prone to saying: Go with the trail. It's not rocket science, but pay attention. There are a lot of dumb people everywhere.

[Gaiter]

one of the things to think about is the way sleeping bags work, they need air btn you and the bag to warm up, will combining the two compress each other and reduce functionality?

[scope]

I've done this before and it works great. I only do it car camping, though, as I can't afford the bulk in my pack. If you can, then here is my opinion...

In general, summer bags tend to be cut more loosely, so probably better to put it on the outside. Instead of thinking of the summer bag as a nice liner, think of it as a temperature shield that helps the winter bag do its job more efficiently. Either way, you're probably going to lose some loft, but it will be made up by the fact that the inner bag does not directly contact the cold night air. Your 15 bag now performs at 15 or better, instead of 25-30.

For normal conditions, freezing and above, you can lie in one and 'quilt' the other to give yourself some temp flexibility.

[weary]

Yes, you can layer two sleeping bags. Works pretty well as long as they fit well and one doesn't compress the insulation of the other.

If your main bag is comfortable for you down to 25 or so, you'll likely get some colder nights than that. You can always try this bag combo at home when we get a cold snap.
among the many myths, is the myth that one can compress insulation by hand so that it no longer insulates. Yes. If you sleep on a weak pad, you may wake up cold. That's because lying on insulation in fact somewhat diminishes abolute insulation value.

That's not true for someone just trying to sleep as best as possible.